Foam plug generator



Sept. 19, 1967 c. ANTHONY, JR

FOAM PLUG GENERATOR Filed March 23, 1965 AMBIENT AIR L INVENTOR CHARLES AN ONY JR.

United States Pate'nt C 3,342,271 FOAM PLUG GENERATOR Charles Anthony, Jr., Livingston, N.J., assignor to Specialties Development Corporation, Belleville, N.J., a corporation of New Jersey Filed Mar. 23, 1965, Ser. No. 442,087 3 Claims. (Cl. 169-15) The present invention relates to fire more particularly to improved a fire-fighting foam plug.

United States Patent No. 3,142,340 discloses such apparatus which essentially comprises a wind tunnel, a foam forming net at one end of the tunnel, an electric motor driven fan at the other end of the tunnel, and spray nozzle between the fan and the net for directing onto the net sprays of water containing a foaming agent. This apparatus is intended to be operated by an unlimited supply of water from a water line, an unlimited supply of electricity from a power line for driving the fan and a more than adequate supply of foaming agent so that the apparatus can be operated for a sufficient duration of time to produce a foam plug capable of filling large spaces such as mine tunnels, warehouses and the like.

However, this apparatus cannot be used in spaces on craft or vehicles which lack water and power lines.

Accordingly, an object of the present invention is to provide apparatus of the foregoing type for generating a fire-fighting foam plug for filling spaces on craft or vehicles even while moving.

Another object is to provide such apparatus which does not depend on an unlimited supply of water and/ or electrical power, but which is constructed and arranged to be operated for a sufiicient duration of time to generate a extinguishing, and apparatus for generating foam plug capable of filling the space or spaces on the 1 craft or vehicle without the use of electrical power, except for battery powered control devices, and with the use of a limited supply of water carried on the craft or vehicle.

Another object is to provide such apparatus which is particularly adapted for use on pleasure boats, vans, box cars, tanker trucks or trailers or railway tank cars, and other craft or vehicles where a fire hazard exists.

Another object is to provide such apparatus which can also be installed in fixed spaces of a known volume and can generate sufficient foam to fill such spaces, examples of such spaces being boiler rooms and storage tanks for flammable liquids.

Another object is to provide such apparatus which can be encased as a unit ready for installation at its point of use.

Another object is to provide such apparatus which can be readily recharged after each use thereof.

A further object is to provide such apparatus which is light in weight, compact in arrangement, is economical to manufacture, install and operate, and is reliable and efiicient in operation.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be desecribed, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employement of the invention in practice.

In accordance with the present invention these objects are generally accomplished by providing apparatus for generating a fire-fighting foam plug, which apparatus comprises a wind tunnel; a foam forming net at one end of the tunnel; an aspirator at the other end of the tunnel including an air entraining tube having an inlet at one end and a outlet at the other end facing the net for delivering air into the tunnel flowing towards the 3,342,271 Patented Sept. 19, 19s? net, and nozzle means at the inlet end for directing gaseous medium under pressure into the tube to effect air entrainment; and spray means in the tunnel between the net and the aspirator for directing onto the net a solution containing a foaming agent, whereby the air delivered into the tunnel causes the solution deposited on the net to foam and generate the foam plug.

A preferred embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompany drawing, forming a part of the specification, wherein:

The single figure is a schematic view, partly in elevation and partly in section, illustrating apparatus in accordance with the present invention.

Referring now to the drawing in detail, apparatus is shown which generally comprises a wind tunnel 10, a foam forming net 11 at one end of the tunnel, an aspirator 12 at the other end of the tunnel, a source of compressed air 14 for operating the aspirator, spray means such as one or more nozzles 15 in the tunnel between the net and the aspirator for directing onto the net a Water solution containing a foaming agent, and a source 16 for the solution.

The wind tunnel 10 may be rectangular or circular in cross-section. The tunnel is open at its ends to discharge the foam at the net end and to admit air at the aspirator end.

The aspirator 12 for purposes of illustration includes a Wall 17 fitted in the wind tunnel and provided with a central opening 18, a tube 19 having an inlet section 20 mounted on the wall 17 and provided with an outlet section 21 fitted in the opening 18 and facing the net 11, and nozzle means 22 at the inlet section 20 such as one or more nozzles or an aperture ring for directing primary air under pressure into the inlet section 20 to effect entrainment of secondary or ambient air.

The source 14 of compressed air as shown herein includes a tank 24, a discharge control valve 25 for the outlet of the tank which valve is operable manually or by any conventional devices responsive to overheat, fire or the like, a conduit 26 connecting the outlet of the valve 25 to the inlet of the nozzle means 22, and a pressure regulator 27 connected in the conduit 26 for supplying air to the aspirator at a uniform predetermined pressure and flow rate.

While a source of high pressure air is illustrated herein, it is contemplated that other types of gaseous media under pressure could be utilized to operate the aspirator Where the conditions of use of the apparatus permit. For example, the gaseous medium could be carbon dioxide or nitrogen or the combustion products of pyrotechnic cool gas generators. The latter media has the additional advantage of inerting the entrained air to reduce the oxygen content of the total volume of the gases passing through the wind tunnel.

The source 16 of foam containing solution shown herein includes a tank 28 having an outlet 29 and an inlet 30, a syphon tube 31 connected to the outlet 29 and extending to the bottom of the tank, a conduit 32 connecting the outlet 29 to the inlet of the spray means 15, and a conduit 34 connected to the conduit 26 downstream of the regulator 27 and to the tank inlet 36 so as to provide a pressure head of a reduced uniform and predetermined pressure for expelling the solution upwardly through the Syphon tube 31. If desired, an air fiow control valve 35 is connected in the conduit 34, and a solution flow control valve 36 is connected in the conduit 32 to provide for independent flow rate control adjustment of the air and the solution.

Alternatively, the solution could be stored in a conventional arrangement which comprises a tank, a bladder confined in the tank containing the solution and having an outlet connected to the conduit 32 and an inlet for the tank so located to admit air from the conduit 34 into the tank to collapse the bladder and squeeze out the solution. Such an arrangement permits the amounts of solution and air to be more accurately proportioned so that practically all of the solution is discharged from the bladder when air flow through the aspirator ceases.

While the foam generating solution source is illustrated herein as containing the foaming agent, it is contemplated that the foaming agent and the water could be stored separately and that the foaming agent could be entrained into the Water before it reaches the spray means 15 by an arrangement such as shown in Patent No. 3,142,340.

A specific example of apparatus in accordance with the present invention comprises a tunnel having an overall length of about two feet, a circular net 11 having an area of about 1.35 square feet, a foaming solution tank 28 having a capacity of about 325 cubic inches, an air tank 24 having a capacity of about 150 cubic inches and containing air at 3000 p.s.i.g. delivery pressure, and an aspirator having a ratio of total air to primary air of about 10.5 to 1.

Such apparatus produces highly expanded foam in excess of 1000 to 1, that is, about 1000 volumes of foam can be generated from one volume of the solution sprayed onto the net. The amount of foam generated completely fills a 180 cubic foot space in about twelve seconds, the foam having a flow rate of about 900 cubic feet a minute when using a 1.35 square foot net.

In so operating the apparatus, it is desirable as a factor of safety to provide suflicient amounts of compressed air and solution to generate a slightly greater amount of foam than is required to completely fill the space.

Also, it is desirable to provide an amount of solution slightly in excess of the amount required to generate a foam plug with a given amount of air so that the pressure of air in the tank 24 decays to 150 psig. and air flow through the regulator ceases before all the solution has been forced out of the tank 287 This prevents air from being discharged through the nozzle 15 or from being suplied through the aspirator after flow of the solution ceases.

From the foregoing description, it will be seen that the present invention provides a novel and useful foam plug generator.

I claim:

1. In apparatus for generating a highly expanded firefighting foam plug, the combination of a wind tunnel; a foam forming net at one end of said tunnel; an aspirator at the other end of said tunnel having a high total air to primary air ratio and including an unobstructed air entraining tube having an inlet at one end and an outlet at the other end facing said net for delivering a large volume of air into said tunnel which flows towards said net, and nozzle means at said inlet for directing gaseous medium under pressure into said tube to effect air entrainment; spray means in said tunnel between said net and said aspirator for directing onto said net a solution containing a foaming agent, whereby the air delivered into said tunnel causes the solution deposited on said net to foam and generate the foam plug; a source of foaming solution; first conduit means connecting said source of solution to said spray means; second conduit means connecting said source of gaseous medium to said nozzle means and to said source of solution for applying a pressure head on the solution to expel the same from said source; and pressure regulating means in said second conduit means upstream of said nozzle means and said source of solution for reducing the pressure of the gaseous medium.

2. In apparatus according to claim 1, including valve means in said first and second conduit means for independently controlling the flow rate of the gaseous medium and the solution.

3. In apparatus according to claim 1, wherein said gaseous medium under pressure and said foaming solution are in a proportion to produce a predetermined volume of high expanded foam.

References Cited UNITED STATES PATENTS 2,630,183 3/1953 Foutz 239-432 2,766,026 10/ 1956 Boyd.

2,862,765 12/1958 Wing 239303 3,094,171 6/ 1963 Gagliardo 239-399 3,109,594 11/1963 Fletcher 239-422 3,186,490 6/ 1965 Jamison et al. 1692 EVERETT W. KIRBY, Primary Examiner.

M. HENSON WOOD, JR., Examiner.

R. S. STROBEL, Assistant Examiner. 

1. IN APPARATUS FOR GENERATING A HIGHLY EXPANDED FIREFIGHTING FOAM PLUG, THE COMBINATION OF A WIND TUNNEL; A FOAM FORMING NET AT ONE END OF SAID TUNNEL; AN ASPIRATOR AT THE OTHER END OF SAID TUNNEL HAVING A HIGH TOTAL AIR TO PRIMARY AIR RATIO AND INCLUDING AN UNOBSTRUCTED AIR ENTRAINING TUBE HAVING AN INLET AT ONE END AND AN OUTLET AT THE OTHER END FACING SAID NET FOR DELIVERING A LARGE VOLUME OF AIR INTO SAID TUNNEL WHICH FLOWS TOWARDS SAID NET, AND NOZZLE MEANS AT SAID INLET FOR DIRECTING GASEOUS MEDIUM UNDER PRESSURE INTO SAID TUBE TO EFFECT AIR ENTRAINMENT; SPRAY MEANS IN SAID TUNNEL BETWEEN SAID NET AND SAID ASPIRATOR FOR DIRECTING ONTO SAID NET A SOLUTION CONTAINING A FOAMING AGENT, WHEREBY THE AIR DELIVERED INTO SAID TUNNEL CAUSES THE SOLUTION DEPOSITED ON SAID NET TO FOAM AND GENERATE THE FOAM PLUG; A SOURCE OF FOAMING SOLUTION; FIRST CONDUIT MEANS CONNECTING SAID SOURCE OF SOLUTION TO SAID SPRAY MEANS; SECOND CONDUIT MEANS CONNECTING SAID SOURCE OF GASEOUS MEDIUM TO SAID NOZZLE MEANS AND TO SAID SOURCE OF SOLUTION FOR APPLYING A PRESSURE HEAD ON THE SOLUTION TO EXPEL THE SAME FROM SAID SOURCE; AND PRESSURE REGULATING MEANS IN SAID SECOND CONDUIT MEANS UPSTREAM OF SAID NOZZLE MEANS AND SAID SOURCE OF SOLUTION FOR REDUCING THE PRESSURE OF THE GASEOUS MEDIUM. 